The present invention generally relates to coverings for pickup trucks and, more particularly, relates to a roll up tonneau cover system.
Tonneau covers have been used for a number of years to cover the cargo box of pickup trucks against dirt, debris, and other environmental contaminants and to improve the aesthetic quality thereof. Originally, tonneau covers were designed by upholstery shops and typically made of vinyl covered fabrics or canvas. The material was often doubled over along its edges for added strength and appearance. Male snaps were then attached to the sides of the cargo box of the pickup truck via fasteners, while female snaps were attached along the edges of the cover. Wooden bows were sometimes used to span the cargo box and ensure that the cover remained high enough to drain water. Unfortunately, these covers were sometimes difficult to handle, often led to corrosion around the snaps, and occasionally failed to protect the cargo box.
However, in the ""70""s, in an attempt to overcome the corrosion around the snaps, tonneau rails were removably mounted to the cargo box of the pickup truck using clamps. These tonneau rails carried the aforementioned snaps and, thus, eliminated the need to mount the snaps directly to the walls of the cargo box.
With the advent of the VELCRO(copyright) hook-and-loop fastening system, tonneau cover systems were developed that included gluing one of the hook or loop strips to the pickup truck and sewing the other strip to the fabric tonneau cover material to effect a simple connection without altering the vehicle body. An example of this system is shown in U.S. Pat. No. 4,272,119, issued to Adams. The disclosure of which is hereby incorporated and made a part of this application by reference. However, the tonneau cover of Adams had a problem remaining attached near the front of the cargo box, most likely due to wind forces. This problem was overcome using a rod of stiff rope or fiberglass sewn into a flap along the front of the tonneau cover. This rod was received within a channel having a xe2x80x9cbitexe2x80x9d mounted near the front of the cargo box to retain the tonneau cover in an attached position.
Rotating rails were later developed to fasten and tighten a tonneau cover. One such system employed two side rails running longitudinally down the sides of the cargo box of the pickup vehicle. A second rail was pivotally attached to each of the two side rails and carried the fabric tonneau cover such that upon downward rotation of the second rails, the fabric tonneau cover was pulled tight. The second rails were then locked in connection with the side rails. This system further included VELCRO(copyright) fasteners along the front and rear edges and a zipper for separating left and right halves. An example of this system can be seen in U.S. Pat. No. 4,036,521, issued to Clenet. The disclosure of which is hereby incorporated and made a part of this application by reference.
Similar to the above system, a tongue and groove connector system is also known for detachably fastening a stretchable fabric panel to a rigid frame. The tongue and groove connector system included a tongue-forming element attached along a line intermediate the side edges thereof to the stretchable fabric panel. The tongue being insertable into a groove with a projecting portion extending there beyond which defines a handhold. The connection requires the fabric to be stretched to a point where the leading edge of the tongue lies adjacent the entryway into the groove such that the stretched fabric pulls the tongue into seated relation in the bottom of the groove. An example of this system can be seen in U.S. Pat. No. 4,757,854, issued to Rippberger. The disclosure of which is hereby incorporated and made a part of this application by reference.
Similarly, the convertible boot cover for the 1980 FORD(copyright) Mustang includes a trim strip around a boot having a slot for inserting a polymer tongue that is sewn to the cover. The tongue is toggled into the slot providing an attachment for the cover. This attachment is similar to that of Rippberger ""854.
Further development of tonneau systems led to the use of 45xc2x0 angled frame rails to improve the aesthetic quality of the tonneau cover. The angled frame rails carried a snap connector for retaining the tonneau cover material. Often, these systems included a double layer of tonneau cover material in the region of the snaps for added reinforcement. Such systems also included a clamp system for coupling with the sidewalls of the cargo box. One such clamp system used a clamp that xe2x80x9cbottomed outxe2x80x9d to prevent over stressing the sidewalls of the cargo box. Examples of these systems can be seen in U.S. Pat. Nos. 4,730,866 and 4,838,602, issued to Nett. The disclosures of which are hereby incorporated and made a part of this application by reference.
Many of these previous features were incorporated in later designs"" with slight modifications. For example, U.S. Pat. No: 5,076,338, similar to U.S. Pat. No. 4,036,521, employed a pivoting rail to tighten the tonneau cover material. In this particular system, an xe2x80x9cLxe2x80x9d shaped rail, which presumably puts the pivot lower for added mechanical advantage, was used to tighten the tonneau cover material from a fore and aft position, rather than cross-car position. This system further employed the 45xc2x0 angled frame rails and VELCRO(copyright) fasteners. The frame rails are coupled to the sidewalls of the cargo box using a plurality of C-clamps. Furthermore, the system included a double layer of tonneau cover material in the region of the snaps for added reinforcement as seen in previous designs.
In a more recent design, a rotating rear rail was provided that included positioning the pivot near the upper surface of the tonneau to minimize torque exerted on the rear rail. The lower torque of this system permitted the use of relatively lightweight plastic levers to lock the rear rail and prevent it from rotating. The combination of the length of these plastic levers and high pivot locations enabled the loads exerted on the levers to be about {fraction (1/12)} th that of the tonneau cover material. Springs were also taught that enabled the automatic tensioning of the tonneau cover material. An example of this system can be seen in commonly owned U.S. Pat. No. 5,251,951, issued to Wheatley. The disclosure of which is hereby incorporated and made a part of this application by reference.
Relatively recently, a tonneau cover system having a screw adjustment mechanism was developed for permitting the fore and aft adjustment of the front rail. This screw adjustment mechanism serves to tighten the tonneau cover material in response to wear and/or stretch that is common in tonneau cover systems. The tonneau cover system further employed the xe2x80x9cLxe2x80x9d shaped lever and lower-positioned pivot, which unfortunately requires the lever to carry an enormous amount of force. That is, by way of example, assuming a 1xe2x80x3 thick rail with a xc2xdxe2x80x3 offset to the latching pivot, a 30-pound tarp load will impart a 60-pound load on the lever. Consequently, a stronger latch is required to overcome these loading forces and minimize wear and breakage. Frame rails are coupled to the sidewalls of the cargo box using a plurality of C-clamps. An example of this system can be seen in U.S. Pat. No. 5,906,407, issued to Schmeichels. The disclosure of which is hereby incorporated and made a part of this application by reference.
A TRUXEDO cover, which is not believed to be patented, made by SHURCO includes a rotating, rectangular, rear rail having a rounded front pivot, vertical sides with VELCRO(copyright) attachment, and spring pins that push on a front rail mounted inboard of the side rails. These spring pins push against the front rail to tension the system in the fore-aft direction. The spring pins, which are attached to the side rails via brackets, may not firmly engage the front rail due to their inboard location which may cause the brackets to come out of alignment as the side rails rotate. Additionally, the rounded shape of the front rails may cause the push pins to slip off-center.
Lastly, U.S. Pat. No. 6,293,608, issued to Dicke, et al., discloses a tailgate rail interconnected to side rails with an interconnecting plate fixedly coupled to the side rails and slideably coupled to the corner piece for accommodating relative movement therebetween. A biasing device, being a coil spring, is further provided. This system provides tensioning to the tonneau fabric.
According to the principles of the present invention, a tonneau system for a cargo box of a vehicle having an advantageous construction is provided. The tonneau cover system includes a support frame, a cover spanning the support frame, and a clamp. The support frame includes side rails having an inboard section and an outboard section, such that the outboard section is positioned adjacent to the top surface of the sidewall of the cargo box so as to aid in the supporting and positioning of the support frame. The clamp is capable of hanging from the support frame during installation to improve the ease thereof. The clamp also includes a pair of members being positionable in any one of a plurality of discrete positions for improved installation. A front rail adjustment mechanism permits the selective tensioning of the cover to maintain a predetermined load therein. While a front rail retaining mechanism is slidably coupled to the front rail member to prevent the front rail member from being inadvertently disengaged from the side rail members. A rear rail retaining mechanism is used to lock the rear rail member or unlock the rear rail member and urge the rear rail member upward.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.